I learned that Bohr explained line spectra by postulating that electrons can only be at certain discrete distances from the nucleus. Later, this theory was refuted/improved by de Broglie and Schrödinger. Since their theories, electrons were seen as standing waves and we can only know where they will probably be. The regions with $90\%$ probability are called orbitals. But how can line spectra be explained if electrons are not restricted to discrete distances but rather to orbital regions?
By the way, am I getting the idea of orbitals correctly ? Is it correct to see it as a region with a high probability of finding an electron as a standing wave?